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Kulakova AM, Khrenova MG, Nemukhin AV. Non-Equivalence of Monomers in the Dimeric Structure of a Bacterial Photoactivated Adenylyl Cyclase. Biophysics (Nagoya-shi) 2022. [DOI: 10.1134/s0006350922060112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023] Open
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2
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Roy P, Roy S, Sengupta N. Disulfide Reduction Allosterically Destabilizes the β-Ladder Subdomain Assembly within the NS1 Dimer of ZIKV. Biophys J 2020; 119:1525-1537. [PMID: 32946768 DOI: 10.1016/j.bpj.2020.08.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 08/13/2020] [Accepted: 08/31/2020] [Indexed: 12/14/2022] Open
Abstract
The Zika virus (ZIKV) was responsible for a recent debilitating epidemic that till date has no cure. A potential way to reduce ZIKV virulence is to limit the action of the nonstructural proteins involved in its viral replication. One such protein, NS1, encoded as a monomer by the viral genome, plays a major role via symmetric oligomerization. We examine the homodimeric structure of the dominant β-ladder segment of NS1 with extensive all atom molecular dynamics. We find it stably bounded by two spatially separated interaction clusters (C1 and C2) with significant differences in the nature of their interactions. Four pairs of distal, intramonomeric disulfide bonds are found to be coupled to the stability, local structure, and wettability of the interfacial region. Symmetric reduction of the intramonomeric disulfides triggers marked dynamical heterogeneity, interfacial wettability, and asymmetric salt-bridging propensity. Harnessing the model-free Lipari-Szabo based formalism for estimation of conformational entropy (Sconf), we find clear signatures of heterogeneity in the monomeric conformational entropies. The observed asymmetry, very small in the unperturbed state, expands significantly in the reduced states. This allosteric effect is most noticeable in the electrostatically bound C2 cluster that underlies the greatest stability in the unperturbed state. Allosteric induction of conformational and thermodynamic asymmetry is expected to affect the pathways leading to symmetric higher-ordered oligomerization, and thereby affect crucial replication pathways.
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Affiliation(s)
- Priti Roy
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, India
| | - Subhajit Roy
- Centre for Excellence in Basic Sciences (CBS), University of Mumbai, Vidyanagari, Mumbai, India
| | - Neelanjana Sengupta
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, India.
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3
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Aleksandrova AA, Sarti E, Forrest LR. MemSTATS: A Benchmark Set of Membrane Protein Symmetries and Pseudosymmetries. J Mol Biol 2019; 432:597-604. [PMID: 31628944 DOI: 10.1016/j.jmb.2019.09.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 08/30/2019] [Accepted: 09/23/2019] [Indexed: 02/06/2023]
Abstract
In membrane proteins, symmetry and pseudosymmetry often have functional or evolutionary implications. However, available symmetry detection methods have not been tested systematically on this class of proteins because of the lack of an appropriate benchmark set. Here we present MemSTATS, a publicly available benchmark set of both quaternary- and internal-symmetries in membrane protein structures. The symmetries are described in terms of order, repeated elements, and orientation of the axis with respect to the membrane plane. Moreover, using MemSTATS, we compare the performance of four widely used symmetry detection algorithms and highlight specific challenges and areas for improvement in the future.
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Affiliation(s)
- Antoniya A Aleksandrova
- Computational Structural Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Edoardo Sarti
- Computational Structural Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Lucy R Forrest
- Computational Structural Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA.
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Zhang X, Yuan Y, Wang L, Guo Y, Li M, Li C, Pu X. Use multiscale simulation to explore the effects of the homodimerizations between different conformation states on the activation and allosteric pathway for the μ-opioid receptor. Phys Chem Chem Phys 2018; 20:13485-13496. [PMID: 29726867 DOI: 10.1039/c8cp02016g] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Recently, oligomers of G-protein coupled receptors (GPCRs) have been an important topic in the GPCR fields. However, knowledge about their structures and activation mechanisms is very limited due to the absence of crystal structures reported. In this work, we used multiscale simulations to study the effects of homodimerization between different conformation states on their activation, dynamic behaviors, and allosteric communication pathways for μ-OR. The results indicated that the dimerization of one inactive monomer with either one inactive monomer or one active one could enhance its constitutive activation. However, the conformation state of the other protomer (e.g., active or inactive) can influence the activated extent. The dimerization between the two inactive protomers leads to a negative cooperativity for their activation, which should contribute to the asymmetric activation of GPCR dimers observed in some experiments. On the other hand, for the active monomer, its dimerization with one inactive receptor could alleviate its deactivation, whereby negative and positive cooperativities can be observed between the two subunits of the dimer, depending on the different regions. Observations from protein structure network (PSN) analysis indicated that the dimerization of one inactive monomer with one active one would cause a significant drop in the number of main pathways from the ligand binding pocket to the G-protein coupled region for the inactive protomer, while the impact is minor for the active protomer. But, for the active monomer or the inactive one, its dimerization with one inactive monomer would significantly change the types of residues participating in the pathway with the highest frequency.
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Affiliation(s)
- Xi Zhang
- College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, People's Republic of China.
| | - Yuan Yuan
- College of Management, Southwest University for Nationalities, Chengdu 610041, P. R. China
| | - Longrong Wang
- College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, People's Republic of China.
| | - Yanzhi Guo
- College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, People's Republic of China.
| | - Menglong Li
- College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, People's Republic of China.
| | - Chuan Li
- College of Computer Science, Sichuan University, Chengdu, Sichuan 610064, P. R. China.
| | - Xuemei Pu
- College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, People's Republic of China.
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5
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Signalling assemblies: the odds of symmetry. Biochem Soc Trans 2017; 45:599-611. [PMID: 28620024 DOI: 10.1042/bst20170009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 02/27/2017] [Accepted: 02/28/2017] [Indexed: 02/06/2023]
Abstract
The assembly of proteins into complexes is fundamental to nearly all biological signalling processes. Symmetry is a dominant feature of the structures of experimentally determined protein complexes, observed in the vast majority of homomers and many heteromers. However, some asymmetric structures exist, and asymmetry also often forms transiently, intractable to traditional structure determination methods. Here, we explore the role of protein complex symmetry and asymmetry in cellular signalling, focusing on receptors, transcription factors and transmembrane channels, among other signalling assemblies. We highlight a recurrent tendency for asymmetry to be crucial for signalling function, often being associated with activated states. We conclude with a discussion of how consideration of protein complex symmetry and asymmetry has significant potential implications and applications for pharmacology and human disease.
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6
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Bergendahl LT, Marsh JA. Functional determinants of protein assembly into homomeric complexes. Sci Rep 2017; 7:4932. [PMID: 28694495 PMCID: PMC5504011 DOI: 10.1038/s41598-017-05084-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 05/24/2017] [Indexed: 11/24/2022] Open
Abstract
Approximately half of proteins with experimentally determined structures can interact with other copies of themselves and assemble into homomeric complexes, the overwhelming majority of which (>96%) are symmetric. Although homomerisation is often assumed to a functionally beneficial result of evolutionary selection, there has been little systematic analysis of the relationship between homomer structure and function. Here, utilizing the large numbers of structures and functional annotations now available, we have investigated how proteins that assemble into different types of homomers are associated with different biological functions. We observe that homomers from different symmetry groups are significantly enriched in distinct functions, and can often provide simple physical and geometrical explanations for these associations in regards to substrate recognition or physical environment. One of the strongest associations is the tendency for metabolic enzymes to form dihedral complexes, which we suggest is closely related to allosteric regulation. We provide a physical explanation for why allostery is related to dihedral complexes: it allows for efficient propagation of conformational changes across isologous (i.e. symmetric) interfaces. Overall we demonstrate a clear relationship between protein function and homomer symmetry that has important implications for understanding protein evolution, as well as for predicting protein function and quaternary structure.
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Affiliation(s)
- L Therese Bergendahl
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, EH4 2XU, UK.
| | - Joseph A Marsh
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, EH4 2XU, UK
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Cooley RB, O’Donnell JP, Sondermann H. Coincidence detection and bi-directional transmembrane signaling control a bacterial second messenger receptor. eLife 2016; 5:e21848. [PMID: 28001128 PMCID: PMC5231407 DOI: 10.7554/elife.21848] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 12/20/2016] [Indexed: 12/15/2022] Open
Abstract
The second messenger c-di-GMP (or cyclic diguanylate) regulates biofilm formation, a physiological adaptation process in bacteria, via a widely conserved signaling node comprising a prototypical transmembrane receptor for c-di-GMP, LapD, and a cognate periplasmic protease, LapG. Previously, we reported a structure-function study of a soluble LapD•LapG complex, which established conformational changes in the receptor that lead to c-di-GMP-dependent protease recruitment (Chatterjee et al., 2014). This work also revealed a basal affinity of c-di-GMP-unbound receptor for LapG, the relevance of which remained enigmatic. Here, we elucidate the structural basis of coincidence detection that relies on both c-di-GMP and LapG binding to LapD for receptor activation. The data indicate that high-affinity for LapG relies on the formation of a receptor dimer-of-dimers, rather than a simple conformational change within dimeric LapD. The proposed mechanism provides a rationale of how external proteins can regulate receptor function and may also apply to c-di-GMP-metabolizing enzymes that are akin to LapD.
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Affiliation(s)
- Richard B Cooley
- Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, United States
| | - John P O’Donnell
- Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, United States
| | - Holger Sondermann
- Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, United States
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Jiang Y, Yuan Y, Zhang X, Liang T, Guo Y, Li M, Pu X. Use of network model to explore dynamic and allosteric properties of three GPCR homodimers. RSC Adv 2016. [DOI: 10.1039/c6ra18243g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
We used an elastic network model and protein structure network to study three class A GPCR homodimers.
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Affiliation(s)
- Yuanyuan Jiang
- College of Chemistry
- Sichuan University
- Chengdu
- P. R. China
| | - Yuan Yuan
- College of Management
- Southwest University for Nationalities
- Chengdu 610064
- P. R. China
| | - Xi Zhang
- College of Chemistry
- Sichuan University
- Chengdu
- P. R. China
| | - Tao Liang
- College of Chemistry
- Sichuan University
- Chengdu
- P. R. China
| | - Yanzhi Guo
- College of Chemistry
- Sichuan University
- Chengdu
- P. R. China
| | - Menglong Li
- College of Chemistry
- Sichuan University
- Chengdu
- P. R. China
| | - Xumei Pu
- College of Chemistry
- Sichuan University
- Chengdu
- P. R. China
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Simon Á, Bencsura Á, Héja L, Magyar C, Kardos J. Sodium-assisted formation of binding and traverse conformations of the substrate in a neurotransmitter sodium symporter model. Curr Drug Discov Technol 2015; 11:227-33. [PMID: 25138914 PMCID: PMC4443782 DOI: 10.2174/1570163811666140812110735] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2014] [Revised: 07/31/2014] [Accepted: 07/31/2014] [Indexed: 11/22/2022]
Abstract
Therapeutics designed to increase synaptic neurotransmitter levels by inhibiting neurotransmitter sodium symporters (NSSs) classify a strategic approach to treat brain disorders such as depression or epilepsy, however, the critical elementary steps that couple downhill flux of sodium to uphill transport of neurotransmitter are not distinguished as yet. Here we present modelling of NSS member neuronal GAT1 with the substrate γ-aminobutyric acid (GABA), the major inhibitory neurotransmitter. GABA binding is simulated with the occluded conformation of GAT1 homodimer in an explicit lipid/water environment. Simulations performed in the 1-10 ns range of time elucidated persistent formation of halfextended minor and H-bridged major GABA conformations, referred to as binding and traverse conformations, respectively. The traverse GABA conformation was further stabilized by GAT1-bound Na(+)(1). We also observed Na(+)(1) translocation to GAT1-bound Cl(-) as well as the appearance of water molecules at GABA and GAT1-bound Na(+)(2), conjecturing causality. Scaling dynamics suggest that the traverse GABA conformation may be valid for developing substrate inhibitors with high efficacy. The potential for this finding is significant with impact not only in pharmacology but wherever understanding of the mechanism of neurotransmitter uptake is valuable.
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Affiliation(s)
| | | | | | | | - Julianna Kardos
- Institute of Molecular Pharmacology, Research Centre for Natural Sciences, PO Box 17, H-1525 Budapest, Hungary.
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Structural and evolutionary versatility in protein complexes with uneven stoichiometry. Nat Commun 2015; 6:6394. [PMID: 25775164 DOI: 10.1038/ncomms7394] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 01/25/2015] [Indexed: 12/20/2022] Open
Abstract
Proteins assemble into complexes with diverse quaternary structures. Although most heteromeric complexes of known structure have even stoichiometry, a significant minority have uneven stoichiometry--that is, differing numbers of each subunit type. To adopt this uneven stoichiometry, sequence-identical subunits must be asymmetric with respect to each other, forming different interactions within the complex. Here we first investigate the occurrence of uneven stoichiometry, demonstrating that it is common in vitro and is likely to be common in vivo. Next, we elucidate the structural determinants of uneven stoichiometry, identifying six different mechanisms by which it can be achieved. Finally, we study the frequency of uneven stoichiometry across evolution, observing a significant enrichment in bacteria compared with eukaryotes. We show that this arises due to a general increased tendency for bacterial proteins to self-assemble and form homomeric interactions, even within the context of a heteromeric complex.
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Yu D, Ma X, Tu Y, Lai L. Both piston-like and rotational motions are present in bacterial chemoreceptor signaling. Sci Rep 2015; 5:8640. [PMID: 25728261 PMCID: PMC4345343 DOI: 10.1038/srep08640] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Accepted: 01/28/2015] [Indexed: 01/16/2023] Open
Abstract
Bacterial chemotaxis signaling is triggered by binding of chemo-effectors to the membrane-bound chemoreceptor dimers. Though much is known about the structure of the chemoreceptors, details of the receptor dynamics and their effects on signaling are still unclear. Here, by using molecular dynamics simulations and principle component analysis, we study the dynamics of the periplasmic domain of aspartate chemoreceptor Tar dimer and its conformational changes when binding to different ligands (attractant, antagonist, and two attractant molecules). We found two dominant components (modes) in the receptor dynamics: a relative rotation of the two Tar monomers and a piston-like up-and-down sliding movement of the α4 helix. These two modes are highly correlated. Binding of one attractant molecule to the Tar dimer induced both significant piston-like downward movements of the α4 helix and strong relative rotations of the two Tar monomers, while binding of an antagonist or the symmetric binding of two attractant molecules to a Tar dimer suppresses both modes. The anti-symmetric effects of the relative rotation mode also explained the negative cooperativity between the two binding pockets. Our results suggest a mechanism of coupled rotation and piston-like motion for bacterial chemoreceptor signaling.
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Affiliation(s)
- Daqi Yu
- 1] BNLMS, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing. 100871, China [2] Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing. 100871, China
| | - Xiaomin Ma
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing. 100871, China
| | - Yuhai Tu
- 1] Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing. 100871, China [2] IBM T. J. Watson Research Center, Yorktown Heights, New York 10598, USA
| | - Luhua Lai
- 1] BNLMS, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing. 100871, China [2] Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing. 100871, China [3] Peking-Tsinghua Center for Life Sciences, Peking University, Beijing. 100871, China
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